Inkjet printers print by ejecting ink through the nozzles of a print cartridge onto a print medium. An ink supply, which may be contained within the cartridge or located remotely, serves to supply ink to the nozzles. Because the nozzles typically have relatively small flow areas, particulate matter can clog the nozzles, disrupting or reducing printing performance. Surfaces that are exposed to the ink, such as those within the cartridge or separate ink supply, are common sources of disruptive particulate matter.
In the past, woven metal filters have been inserted between the ink supply and the print cartridge nozzles to prevent any particles from reaching the nozzles. Unfortunately, the woven metal filters themselves may be susceptible to carrying and releasing particulate matter that can clog the nozzles. Furthermore, the use of woven metal filters may reduce the types of inks that can be used because some desirable inks are highly corrosive to the woven metal filters. Moreover, many past filters have had less than desirable filtration efficiencies within certain pressure drop ranges.
Therefore, there is a need for a filter having high filtration efficiency at a wide range of pressure drops. In addition, there is a need for a clean filter that can withstand highly corrosive chemicals.